Manufacturing lightweight parts such as those used in automotive and aerospace industries requires strong polymer composites. The current state of the art involves prepreg long reinforcing fibers embedded into polymer matrices. The term ‘prepreg’ typically refers to fabric reinforcement that has been pre-impregnated with a resin system. The resin system generally consists of an epoxy that already includes the proper curing agent. Woven carbon fibers and fiberglass fabrics are the materials of choice in the prepreg industry. These materials enable structures with unrivaled mechanical properties, but have many difficulties in fabrication, include being time consuming and somewhat limited in that they can only be made in flat, layered shapes.
In contrast, inexpensive mixing equipment can create composite structures made by mixing and dispersing particle fillers into polymers, which in turn can form any desired shape. However, these particle polymer composite materials cannot achieve the mechanical properties required by the aerospace industry. A great need exists for particle based polymeric structures with mechanical properties approaching those of the prepreg long fiber structures.